for Journals by Title or ISSN
for Articles by Keywords
help

 A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z  

        1 2     

  Subjects -> VETERINARY SCIENCE (Total: 184 journals)
Acta Scientiae Veterinariae     Open Access  
Acta Veterinaria     Open Access  
Acta Veterinaria Brno     Open Access   (Followers: 1)
Acta Veterinaria Hungarica     Full-text available via subscription   (Followers: 1)
Acta Veterinaria Scandinavica     Open Access   (Followers: 1)
Advances in Animal Biosciences     Full-text available via subscription   (Followers: 6)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 7)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Alexandria Journal of Veterinary Sciences     Open Access  
American Journal of Animal and Veterinary Sciences     Open Access   (Followers: 9)
American Journal of Primatology     Hybrid Journal   (Followers: 6)
American Journal of Veterinary Research     Full-text available via subscription   (Followers: 15)
Anatomia, Histologia, Embryologia: Journal of Veterinary Medicine Series C     Hybrid Journal   (Followers: 2)
Animal Behaviour     Hybrid Journal   (Followers: 261)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 6)
Animal Health Research Reviews     Hybrid Journal   (Followers: 4)
Animal Reproduction Science     Hybrid Journal   (Followers: 5)
Animals     Open Access   (Followers: 5)
Annales UMCS, Medicina Veterinaria     Open Access  
Annals of Agricultural and Environmental Medicine     Open Access   (Followers: 1)
Annual Review of Animal Biosciences     Full-text available via subscription   (Followers: 4)
Anthrozoos : A Multidisciplinary Journal of The Interactions of People & Animals     Full-text available via subscription   (Followers: 8)
Archives of Animal Nutrition     Hybrid Journal   (Followers: 5)
Archivos de Medicina Veterinaria     Open Access   (Followers: 1)
Arquivo Brasileiro de Medicina Veterinária e Zootecnia     Open Access   (Followers: 1)
Asian Journal of Poultry Science     Open Access   (Followers: 4)
Atatürk Üniversitesi Veteriner Bilimleri Dergisi     Open Access  
Australian Equine Veterinarian     Full-text available via subscription   (Followers: 1)
Australian Veterinary Journal     Hybrid Journal   (Followers: 10)
Avances en Ciencias Veterinarias     Open Access  
Avian Diseases     Full-text available via subscription   (Followers: 4)
Avian Diseases Digest     Full-text available via subscription   (Followers: 3)
Avian Pathology     Hybrid Journal   (Followers: 2)
Bangladesh Journal of Animal Science     Open Access  
Bangladesh Journal of Veterinary Medicine     Open Access  
BMC Veterinary Research     Open Access   (Followers: 5)
Brazilian Journal of Veterinary Research and Animal Science     Open Access   (Followers: 7)
Bulletin of Animal Health and Production in Africa     Full-text available via subscription  
Bulletin of the Veterinary Institute in Pulawy     Open Access  
Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca : Food Science and Technology     Open Access  
Canadian Journal of Veterinary Research     Full-text available via subscription   (Followers: 7)
Case Reports in Veterinary Medicine     Open Access   (Followers: 4)
Ciência Animal Brasileira     Open Access  
Ciência Rural     Open Access   (Followers: 2)
Companion Animal     Full-text available via subscription   (Followers: 4)
Domestic Animal Endocrinology     Hybrid Journal   (Followers: 3)
Equine Health     Full-text available via subscription  
Equine Veterinary Education     Hybrid Journal   (Followers: 7)
Equine Veterinary Journal     Hybrid Journal   (Followers: 10)
Ethiopian Veterinary Journal     Open Access   (Followers: 2)
Eurasian Journal of Veterinary Sciences     Open Access   (Followers: 1)
Global Journal of Animal Scientific Research     Open Access   (Followers: 1)
Human & Veterinary Medicine - International Journal of the Bioflux Society     Open Access   (Followers: 5)
ILAR Journal     Hybrid Journal  
In Practice     Full-text available via subscription   (Followers: 3)
Indian Journal of Animal Sciences     Open Access   (Followers: 5)
Indian Journal of Veterinary Anatomy     Full-text available via subscription   (Followers: 3)
Intas Polivet     Full-text available via subscription  
International Journal for Agro Veterinary and Medical Sciences     Open Access   (Followers: 3)
International Journal of Livestock Research     Open Access  
International Journal of Veterinary Science and Medicine     Open Access   (Followers: 4)
InVet     Open Access  
Irish Veterinary Journal     Open Access   (Followers: 2)
ISRN Veterinary Science     Open Access  
Journal of Veterinary Science & Technology     Open Access   (Followers: 3)
Journal of Advanced Veterinary and Animal Research     Open Access   (Followers: 5)
Journal of Animal Behaviour and Biometeorology     Open Access   (Followers: 1)
Journal of Animal Physiology and Animal Nutrition     Hybrid Journal   (Followers: 5)
Journal of Animal Science and Technology     Open Access  
Journal of Applied Animal Nutrition     Hybrid Journal   (Followers: 3)
Journal of Avian Medicine and Surgery     Full-text available via subscription   (Followers: 4)
Journal of Equine Veterinary Science     Hybrid Journal   (Followers: 9)
Journal of Exotic Pet Medicine     Full-text available via subscription   (Followers: 2)
Journal of Experimental and Applied Animal Sciences     Open Access   (Followers: 1)
Journal of Feline Medicine & Surgery     Hybrid Journal   (Followers: 4)
Journal of Research in Forestry, Wildlife and Environment     Open Access  
Journal of Small Animal Practice     Hybrid Journal   (Followers: 8)
Journal of the American Veterinary Medical Association     Full-text available via subscription   (Followers: 21)
Journal of the Hellenic Veterinary Medical Society     Full-text available via subscription   (Followers: 2)
Journal of the South African Veterinary Association     Open Access   (Followers: 1)
Journal of Venomous Animals and Toxins     Open Access   (Followers: 3)
Journal of Veterinary Advances     Open Access   (Followers: 4)
Journal of Veterinary Behavior: Clinical Applications and Research     Hybrid Journal   (Followers: 3)
Journal of Veterinary Cardiology     Full-text available via subscription   (Followers: 4)
Journal of Veterinary Diagnostic Investigation     Hybrid Journal   (Followers: 4)
Journal of Veterinary Emergency and Critical Care     Hybrid Journal   (Followers: 10)
Journal of Veterinary Internal Medicine     Hybrid Journal   (Followers: 12)
Journal of Veterinary Medical Education     Partially Free   (Followers: 8)
Journal of Veterinary Medicine     Open Access   (Followers: 4)
Journal of Veterinary Medicine and Animal Health     Open Access   (Followers: 2)
Journal of Veterinary Pharmacology and Therapeutics     Hybrid Journal   (Followers: 4)
Journal of Veterinary Science & Medical Diagnosis     Full-text available via subscription   (Followers: 1)
Journal of Zoo and Aquarium Research     Open Access   (Followers: 1)
Journal of Zoo and Wildlife Medicine     Full-text available via subscription   (Followers: 3)
Kenya Veterinarian     Full-text available via subscription   (Followers: 2)
kleintier konkret     Hybrid Journal  
Kufa Journal For Veterinary Medical Sciences     Open Access  
Livestock     Full-text available via subscription   (Followers: 1)
Macedonian Veterinary Review     Open Access   (Followers: 3)
MEDIA PETERNAKAN - Journal of Animal Science and Technology     Open Access   (Followers: 1)

        1 2     

Journal Cover Veterinary Microbiology
   [10 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 0378-1135 - ISSN (Online) 1873-2542
     Published by Elsevier Homepage  [2575 journals]   [SJR: 1.221]   [H-I: 75]
  • Prevalence and characteristics of Cyprinid herpesvirus 3 (CyHV-3)
           infection in common carp (Cyprinus carpio L.) inhabiting three rivers in
           Kochi Prefecture, Japan
    • Abstract: Publication date: Available online 11 December 2014
      Source:Veterinary Microbiology
      Author(s): Hiroya Fujioka , Kenichi Yamasaki , Keiki Furusawa , Kazuki Tamura , Kazuki Oguro , Sumire Kurihara , Shingo Seki , Syun-ichirou Oshima , Masayuki Imajoh
      Cyprinid herpesvirus 3 (CyHV-3) causes lethal disease in common and koi carp. Mortality by CyHV-3 disease has not been reported since 2011 in Kochi Prefecture, Japan. Here, we detected and quantified CyHV-3 in common carp inhabiting three rivers in the prefecture to examine if the carp are carriers of CyHV-3 as a source of infection. CyHV-3 DNA was detected in 16.7% (12/72) of brain samples in Kagami River, 3.9% (3/76) of brain and 3.9% (3/76) of gill samples in Monobe River, and 5.1% (4/79) of brain and 1.3% (1/79) of gill samples in Wajiki River. CyHV-3 genotypes identified in the 23 samples were classified as the J genotype A1 that has been found in Japan. The CyHV-3 DNA load did not differ statistically between sampling months, indicating that CyHV-3 has been silent in common carp, unlike Lake Biwa where the annual reactivation occurs in spring. Taken together, our results represented definitive evidence that seasonal changes in water temperature do not affect CyHV-3 activity in carp. Considering that infectious virus was not isolated from CyHV-3 DNA-positive samples, it was suggested that CyHV-3 establishes a latent infection in carp populations inhabiting Kagami River, Monobe River and Wajiki River. Further, the presence of circular or concatameric CyHV-3 DNA was detected in five of 23 CyHV-3 DNA-positive samples. Common carp inhabiting Lake Biwa were reported previously to harbor linear but not circular CyHV-3 DNA. This difference suggested that the CyHV-3 genome may be circularized for long-term maintenance without active viral replication.
      Graphical abstract image

      PubDate: 2014-12-16T10:36:42Z
       
  • Identification of a novel herpesvirus in captive Eastern box turtles
           (Terrapene carolina carolina)
    • Abstract: Publication date: Available online 13 December 2014
      Source:Veterinary Microbiology
      Author(s): Richard R. Sim , Terry M. Norton , Ellen Bronson , Matthew C. Allender , Nancy Stedman , April L. Childress , James F.X. Wellehan Jr
      Herpesviruses are significant pathogens of chelonians which most commonly cause upper respiratory tract disease and necrotizing stomatitis. Herpesvirus infection was identified in two populations of captive Eastern box turtles (Terrapene carolina carolina) using histopathology and polymerase chain reaction (PCR) with DNA sequencing. Necrotizing lesions with eosinophilic to amphophilic intranuclear inclusion bodies were identified in the tissues of one hatch-year individual in January 2013, which was herpesvirus positive by PCR. A separate captive group of adults had an observed herpesvirus prevalence of 58% using PCR in July 2011. In these cases, a novel herpesvirus, Terrapene herpesvirus 1 (TerHV1), was identified and serves as the first herpesvirus sequenced in the genus Terrapene. Similar to the other herpesviruses of the Order Testudines, TerHV1 clusters with the genus Scutavirus of the subfamily Alphaherpesvirinae.


      PubDate: 2014-12-16T10:36:42Z
       
  • Factors affecting the infectivity of tissues from pigs with classical
           swine fever: Thermal inactivation rates and oral infectious dose
    • Abstract: Publication date: Available online 13 December 2014
      Source:Veterinary Microbiology
      Author(s): Lucie Cowan , Felicity J. Haines , Helen E. Everett , Bentley Crudgington , Helen L. Johns , Derek Clifford , Trevor W. Drew , Helen R. Crooke
      Outbreaks of classical swine fever are often associated with ingestion of pig meat or products derived from infected pigs. Assessment of the disease risks associated with material of porcine origin requires knowledge on the likely amount of virus in the original material, how long the virus may remain viable within the resulting product and how much of that product would need to be ingested to result in infection. Using material from pigs infected with CSFV, we determined the viable virus concentrations in tissues that comprise the majority of pork products. Decimal reduction values (D values), the time required to reduce the viable virus load by 90% (or 1 log10), were determined at temperatures of relevance for chilling, cooking, composting and ambient storage. The rate of CSFV inactivation varied in different tissues. At lower temperatures, virus remained viable for substantially longer in muscle and serum compared to lymphoid and fat tissues. To enable estimation of the temperature dependence of inactivation, the temperature change required to change the D values by 90% (Z values) were determined as 13°C, 14°C, 12°C and 10°C for lymph node, fat, muscle and serum, respectively. The amount of virus required to infect 50% of pigs by ingestion was determined by feeding groups of animals with moderately and highly virulent CSFV. Interestingly, the virulent virus did not initiate infection at a lower dose than the moderately virulent strain. Although higher than for intranasal inoculation, the amount of virus required for infection via ingestion is present in only a few grams of tissue from infected animals.


      PubDate: 2014-12-16T10:36:42Z
       
  • Diversity of Shiga toxin-producing Escherichia coli in sheep flocks of
           Paraná State, southern Brazil
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Fernando Henrique Martins , Beatriz Ernestina Cabilio Guth , Roxane Maria Piazza , Sylvia Cardoso Leão , Agostinho Ludovico , Marilúcia Santos Ludovico , Ghizlane Dahbi , Juan Marzoa , Azucena Mora , Jorge Blanco , Jacinta Sanchez Pelayo
      Sheep constitute an important source of zoonotic pathogens as Shiga toxin-producing Escherichia coli (STEC). In this study, the prevalence, serotypes and virulence profiles of STEC were investigated among 130 healthy sheep from small and medium farms in southern Brazil. STEC was isolated from 65 (50%) of the tested animals and detected in all flocks. A total of 70 STEC isolates were characterized, and belonged to 23 different O:H serotypes, many of which associated with human disease, including hemolytic-uremic syndrome (HUS). Among the serotypes identified, O76:H19 and O65:H– were the most common, and O75:H14 and O169:H7 have not been previously reported in STEC strains. Most of the STEC isolates harbored only stx1, whereas the Stx2b subtype was the most common among those carrying stx2. Enterohemolysin (ehxA) and intimin (eae) genes were detected in 61 (87.1%) and four (5.7%) isolates, respectively. Genes encoding putative adhesins (saa, iha, lpf O113 ) and toxins (subAB and cdtV) were also observed. The majority of the isolates displayed virulence features related to pathogenesis of STEC, such as adherence to epithelial cells, high cytotoxicity and enterohemolytic activity. Ovine STEC isolates belonged mostly to phylogenetic group B1. PFGE revealed particular clones distributed in some farms, as well as variations in the degree of genetic similarity within serotypes examined. In conclusion, STEC are widely distributed in southern Brazilian sheep, and belonged mainly to serotypes that are not commonly reported in other regions, such as O76:H19 and O65:H–. A geographical variation in the distribution of STEC serotypes seems to occur in sheep.


      PubDate: 2014-12-16T10:36:42Z
       
  • Pseudomonas fluorescens: Fur is required for multiple biological
           properties associated with pathogenesis
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Ze-jun Zhou , Lu Zhang , Li Sun
      Pseudomonas fluorescens, a Gram-negative bacterium, is an aquaculture pathogen with a broad host range. In a previous study, we had demonstrated that knockout of the fur gene of a pathogenic P. fluorescens strain, TSS, resulted in profound virulence attenuation. In this work, we studied the properties of the fur knockout mutant, TFM, in comparison with the wild type strain TSS. We found that compared to TSS, TFM (i) was impaired in siderophore production and extracellular enzyme activities, (ii) exhibited altered global polarity, (iii) was dramatically reduced in the ability to resist oxidative stress, (iv) showed higher tolerance to manganese, and (v) exhibited significantly reduced cytotoxicity. When incubated with cultured host cells, TFM displayed a cellular binding index much lower than that of TSS. Neither TFM nor TSS was able to survive and replicate in host cells. Following inoculation into Japanese flounder (Paralichthys olivaceus), TSS upregulated the expression of a wide range of genes involved in innate immunity, notably IL-1β and two CC chemokines. In contrast, TFM caused significant inductions of only a few genes and to much lower magnitudes than TSS. Given the strong inductions of IL-1β and the two chemokines by TSS, the effect of these three genes on P. fluorescens invasion was examined. The results showed that overexpression of these genes in flounder significantly inhibited TSS dissemination into and colonization of host tissues. Taken together, these results indicate that Fur is required for multiple processes associated with virulence, and that proinflammatory cytokines and chemokines likely play important roles in the clearance of P. fluorescens infection.


      PubDate: 2014-12-16T10:36:42Z
       
  • Fine mapping and conservation analysis of linear B-cell epitopes of peste
           des petits ruminants virus nucleoprotein
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Ruisong Yu , Xiaoming Fan , Wanxiang Xu , Wentao Li , Shijuan Dong , Yumin Zhu , Yaping He , Haiping Tang , Rong Du , Zhen Li
      Nucleoprotein (NP) is the most abundant and highly immunogenic protein of morbillivirus, and is presently the basis of most diagnostic assays for peste des petits ruminants virus (PPRV). In this study, fine epitope mapping and conservation analysis of linear B-cell epitopes on the PPRV NP has been undertaken using biosynthetic peptides. Nineteen linear B-cell epitopes were identified and their corresponding minimal motifs were located on the NP of PPRV China/Tibet/Geg/07-30. Conservation analysis indicated that ten of the 19 minimal motifs were conserved among 46 PPRV strains. Peptides containing the minimal motifs were recognized using anti-PPRV serum from a goat immunized with PPRV vaccine strain Nigeria 75/1. Identified epitopes and their motifs improve our understanding of the antigenic characteristics of PPRV NP and provide a basis for the development of epitope-based diagnostic assays.


      PubDate: 2014-12-16T10:36:42Z
       
  • Effect of booster shot and investigation of vaccination efficacy period
           against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius
           auratus
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Takafumi Ito , Yukio Maeno
      In this study, the efficacy period of an intraperitoneal vaccination and effect of a booster shot of vaccine against herpesviral haematopoietic necrosis (HVHN) in goldfish Carassius auratus were investigated. Cell culture supernatant of cyprinid herpesvirus 2 (CyHV-2), causative agent of HVHN, propagated in goldfish fin (GFF) cells was inactivated with formalin (0.1%, v/v) for 2 days at 4°C. Three groups of the variety Ryukin were individually intraperitoneally injected with the vaccine and each group was separately maintained in replicate tanks. After 4 weeks (Vaccinated-4w-1 and 2) and 8 weeks (Vaccinated-8w-1 and 2) from the first vaccination, the fish were CyHV-2-challenged by the immersion route (10 TCID50 l−1). In addition, the other vaccinated group of fish were injected with a booster vaccine 4 weeks after the first vaccination as the Vaccinated-booster groups, then the fish of these groups were CyHV-2-challenged by the immersion route (10 TCID50 l−1) after 8 weeks from the first vaccination. The mean of the relative percentage survival (RPS) values of the Vaccinated-4w and 8w groups showed 42.5% and 57.6%, respectively. In addition, the mean RPS value of Vaccinated-booster groups showed 63.6%. Statistical analysis showed significantly higher survival rates in all the vaccinated groups than those of the respective negative control groups using Fisher's exact test. Moreover, the survival rates of vaccinated-booster groups were significantly higher (p =0.036) compared with the respective control groups by Student's t test. The present study shows the efficacy period of the vaccine is at least 8 weeks and a booster shot showed a tendency to enhance the protection against HVHN in goldfish.


      PubDate: 2014-12-16T10:36:42Z
       
  • Influence of the major nitrite transporter NirC on the virulence of a
           Swollen Head Syndrome Avian Pathogenic E. coli (APEC) strain
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Jacqueline Boldrin de Paiva , Janaína Luisa Leite , Livia Pilatti Mendes da Silva , Thais Cabrera Galvão Rojas , Fernanda de Pace , Rogério Arcuri Conceição , Vanessa Sperandio , Wanderley Dias da Silveira
      Avian Pathogenic Escherichia coli (APEC) strains are extra-intestinal E. coli that infect poultry and cause diseases. Nitrite is a central branch-point in bacterial nitrogen metabolism and is used as a cytotoxin by macrophages. Unlike nitric oxide (NO), nitrite cannot diffuse across bacterial membrane cells. The NirC protein acts as a specific channel to facilitate the transport of nitrite into Salmonella and E. coli cells for nitrogen metabolism and cytoplasmic detoxification. NirC is also required for the pathogenicity of Salmonella by downregulating the production of NO by the host macrophages. Based on an in vitro microarray that revealed the overexpression of the nirC gene in APEC strain SCI-07, we constructed a nirC-deficient SCI-07 strain (ΔnirC) and evaluated its virulence potential using in vivo and in vitro assays. The final cumulative mortalities caused by mutant and wild-type (WT) were similar; while the ΔnirC caused a gradual increase in the mortality rate during the seven days recorded, the WT caused mortality up to 24h post-infection (hpi). Counts of the ΔnirC cells in the spleen, lung and liver were higher than those of the WT after 48hpi but similar at 24hpi. Although similar number of ΔnirC and WT cells was observed in macrophages at 3hpi, there was higher number of ΔnirC cells at 16hpi. The cell adhesion ability of the ΔnirC strain was about half the WT level in the presence and absence of alpha-d-mannopyranoside. These results indicate that the nirC gene influences the pathogenicity of SCI-07 strain.


      PubDate: 2014-12-16T10:36:42Z
       
  • Divergence of a strain of Pseudomonas aeruginosa during an outbreak of
           ovine mastitis
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Elli A. Wright , Valeria Di Lorenzo , Claudia Trappetti , Manuele Liciardi , Germano Orru , Carlo Viti , Christina Bronowski , Amanda J. Hall , Alistair C. Darby , Marco R. Oggioni , Craig Winstanley
      Bacterial infections causing mastitis in sheep can result in severe economic losses for farmers. A large survey of milk samples from ewes with mastitis in Sardinia, Italy, indicated an increasing prevalence of Pseudomonas aeruginosa infections. It has been shown previously that during chronic, biofilm-associated infections P. aeruginosa populations diversify. We report the phenotypic and genomic characterisation of two clonal P. aeruginosa isolates (PSE305 and PSE306) from a mastitis infection outbreak, representing distinct colony morphology variants. In addition to pigment production, PSE305 and PSE306 differed in phenotypic characteristics including biofilm formation, utilisation of various carbon and nitrogen sources, twitching motility. We found higher levels of expression of genes associated with biofilm formation (pelB) and twitching motility (flgD) in PSE305, compared to the biofilm and twitching-defective PSE306. Comparative genomics analysis revealed single nucleotide polymorphisms (SNPs) and minor insertion/deletion variations between PSE305 and PSE306, including a SNP mutation in the pilP gene of PSE306. By introducing a wild-type pilP gene we were able to partially complement the defective twitching motility of PSE306. There were also three larger regions of difference between the two genomes, indicating genomic instability. Hence, we have demonstrated that P. aeruginosa population divergence can occur during an outbreak of mastitis, leading to significant variations in phenotype and genotype, and resembling the behaviour of P. aeruginosa during chronic biofilm-associated infections.


      PubDate: 2014-12-16T10:36:42Z
       
  • Characterization of Mannheimia haemolytica biofilm formation in vitro
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Ismail Boukahil , Charles J. Czuprynski
      Mannheimia haemolytica is the primary bacterial agent in the bovine respiratory disease complex. It is thought that M. haemolytica colonizes the tonsillar crypts of cattle as a commensal and subsequently descends into the lungs to cause disease. Many bacterial species persist in the host as biofilms. There is limited information about the ability of M. haemolytica to form biofilms. The aim of this study was to develop an in vitro model for M. haemolytica biofilm formation. We found that M. haemolytica required at least 36h to form robust biofilms on plastic in vitro when incubated in RPMI-1640 tissue culture medium at 37°C, with maximal biofilm formation being evident at 48h. Biofilm formation was inhibited by adding the monosaccharides d(+) galactose and d(+) mannose to the growth medium. Addition of antibodies to the M. haemolytica surface protein OmpA also reduced biofilm formation. Upon evaluating the macromolecules within the biofilm extracellular polymeric substance we found it contained 9.7μg/cm2 of protein, 0.81μg/cm2 of total carbohydrate, and 0.47μg/cm2 of extracellular DNA. Furthermore, proteinase K treatment significantly decreased biofilms (P <0.05) while α-amylase and micrococcal nuclease decreased biofilms to a lesser extent. M. haemolytica biofilm cells were more resistant than planktonic cells to the antibiotics florfenicol, gentamicin, and tulathromycin. These results provide evidence that M. haemolytica can form biofilms, which could contribute to its ability to persist as a commensal in the bovine upper respiratory tract.


      PubDate: 2014-12-16T10:36:42Z
       
  • Multiple sampling and discriminatory fingerprinting reveals clonally
           complex and compartmentalized infections by M. bovis in cattle
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Yurena Navarro , Beatriz Romero , María Francisca Copano , Emilio Bouza , Lucas Domínguez , Lucía de Juan , Darío García-de-Viedma
      The combination of new genotyping tools and a more exhaustive sampling policy in the analysis of infection by Mycobacterium tuberculosis has shown that infection by this pathogen is more complex than initially expected. Mixed infections, coexistence of clonal variants from a parental strain, and compartmentalized infections are all different modalities of this clonal complexity. Until recently, genotyping of Mycobacterium bovis in animal populations was based on spoligotyping and analysis of a single isolate per infection; therefore, clonal complexity is probably underdetected. We used multiple sampling combined with highly discriminatory MIRU-VNTR to study compartmentalized infections by M. bovis in a low-tuberculosis prevalence setting. We spoligotyped the M. bovis isolates from two or more anatomic locations sampled from 55 animals on 39 independent farms. Compartmentalized infections, with two different strains infecting independent lymph nodes in the same animal, were found in six cases (10.9%). MIRU-VNTR analysis confirmed that the compartmentalization was strict and that only one strain was present in each infected node. MIRU-VNTR analysis of additional infected animals on one of the farms confirmed that the compartmentalized infection was a consequence of superinfection, since the two strains were independently infecting other animals. This same analysis revealed the emergence of a microevolved clonal variant in one of the lymph nodes of the compartmentalized animal. Clonal complexity must also be taken into consideration in M. bovis infection, even in low-prevalence settings, and analyses must be adapted to detect it and increase the accuracy of molecular epidemiology studies.


      PubDate: 2014-12-16T10:36:42Z
       
  • Effects of different NS genes of avian influenza viruses and amino acid
           changes on pathogenicity of recombinant A/Puerto Rico/8/34 viruses
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Il-Hwan Kim , Hyuk-Joon Kwon , Su-Hyung Lee , Dae-Yong Kim , Jae-Hong Kim
      To examine the effects of the NS1 and NEP genes of avian influenza viruses (AIVs) on pathogenicity in mice, we generated recombinant PR8 viruses containing 3 different NS genes of AIVs. In contrast to the reverse genetics-generated PR8 (rPR8) strain and other recombinant viruses, the recombinant virus rPR8-NS(0028), which contained the NS gene of A/chicken/KBNP-0028/2000 (H9N2) (0028), was non-pathogenic to mice. The novel single mutations of 0028 NS1 to corresponding amino acid of PR8 NS1, G139D and S151T increased the pathogenicity of rPR8-NS(0028). The replacement of the PL motifs (EPEV or RSEV) of pathogenic recombinant viruses with that of 0028 (GSEV) did not reduce the pathogenicity of the viruses. However, a recombinant virus with an EPEV-grafted 0028 NS gene was more pathogenic than rPR8-NS(0028) but less than rPR8. The lower pathogenicity of rPR8-NS(0028) might be associated with the lower virus titer and IFN-β level in the lungs of infected mice, and be attributed to G139, S151 and GSEV-PL motif of NS1 gene of 0028. In conclusion we defined new amino acid residues of NS1 related to mice pathogenicity and the presence of pathogenic NS genes among low pathogenic AIVs may encourage continuous monitoring of their mammalian pathogenicity.
      Graphical abstract image

      PubDate: 2014-12-16T10:36:42Z
       
  • Vaccination with a genotype 1 modified live vaccine against porcine
           reproductive and respiratory syndrome virus significantly reduces viremia,
           viral shedding and transmission of the virus in a quasi-natural
           experimental model
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Emanuela Pileri , Elisa Gibert , Ferran Soldevila , Ariadna García-Saenz , Joan Pujols , Ivan Diaz , Laila Darwich , Jordi Casal , Marga Martín , Enric Mateu
      The present study assessed the efficacy of vaccination against genotype 1 porcine reproductive and respiratory syndrome virus (PRRSV) in terms of reduction of the transmission. Ninety-eight 3-week-old piglets were divided in two groups: V (n =40) and NV (n =58) that were housed separately. V animals were vaccinated with a commercial genotype 1 PRRSV vaccine while NV were kept as controls. On day 35 post-vaccination, 14 NV pigs were separated and inoculated intranasally with 2ml of a heterologous genotype 1 PRRSV isolate (“seeder” pigs, SP). The other V and NV animals were distributed in groups of 5 pigs each. Two days later, one SP was introduced into each pen to expose V and NV to PRRSV. Sentinel pigs were allocated in adjacent pens. Follow-up was of 21 days. All NV (30/30) became viremic after contact with SP while only 53% of V pigs were detected so (21/40, p <0.05). Vaccination shortened viremia (12.2±4 versus 3.7±3.4 days in NV and V pigs, respectively, p <0.01). The 50% survival time for becoming infected (Kaplan–Meier) for V was 21 days (CI95% =14.1–27.9) compared to 7 days (CI95% =5.2–8.7) for NV animals (p <0.01). These differences were reflected in the R value as well: 2.78 (CI95% =2.13–3.43) for NV and 0.53 (CI95% =0.19–0.76) for V pigs (p <0.05). All sentinel pigs (10/10) in pens adjacent to NV+SP pens got infected compared to 1/4 sentinel pigs allocated contiguous to a V+SP pen. These data show that vaccination of piglets significantly decrease parameters related to PRRSV transmission.


      PubDate: 2014-12-16T10:36:42Z
       
  • Multilocus sequence typing of Mycoplasma bovis reveals host-specific
           genotypes in cattle versus bison
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Karen B. Register , Luke Thole , Ricardo F. Rosenbush , F. Chris Minion
      Mycoplasma bovis is a primary agent of mastitis, pneumonia and arthritis in cattle and the bacterium most frequently isolated from the polymicrobial syndrome known as bovine respiratory disease complex. Recently, M. bovis has emerged as a significant health problem in bison, causing necrotic pharyngitis, pneumonia, dystocia and abortion. Whether isolates from cattle and bison comprise genetically distinct populations is unknown. This study describes the development of a highly discriminatory multilocus sequencing typing (MLST) method for M. bovis and its use to investigate the population structure of the bacterium. Genome sequences from six M. bovis isolates were used for selection of gene targets. Seven of 44 housekeeping genes initially evaluated were selected as targets on the basis of sequence variability and distribution within the genome. For each gene target sequence, four to seven alleles could be distinguished that collectively define 32 sequence types (STs) from a collection of 94 cattle isolates and 42 bison isolates. A phylogeny based on concatenated target gene sequences of each isolate revealed that bison isolates are genetically distinct from strains that infect cattle, suggesting recent disease outbreaks in bison may be due to the emergence of unique genetic variants. No correlation was found between ST and disease presentation or geographic origin. MLST data reported here were used to populate a newly created and publicly available, curated database to which researchers can contribute. The MLST scheme and database provide novel tools for exploring the population structure of M. bovis and tracking the evolution and spread of strains.


      PubDate: 2014-12-16T10:36:42Z
       
  • High-level fluoroquinolone resistant Salmonella enterica serovar Kentucky
           ST198 epidemic clone with IncA/C conjugative plasmid carrying blaCTX-M-25
           gene
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Dariusz Wasyl , Izabela Kern-Zdanowicz , Katarzyna Domańska-Blicharz , Magdalena Zając , Andrzej Hoszowski
      Multidrug resistant Salmonella Kentucky strains have been isolated from turkeys in Poland since 2009. Multiple mutations within chromosomal genes gyrA and parC were responsible for high-level ciprofloxacin resistance. One of the isolates was extended spectrum β-lactamase- (ESBL) positive: the strain 1643/2010 carried a conjugative 167,779bps plasmid of IncA/C family. The sequence analysis revealed that it carried a bla CTX-M-25 gene and an integron with another β-lactamase encoding gene—bla OXA-21. This is the first known report of a CTX-M-25 encoding gene both in Poland and in Salmonella Kentucky world-wide, as well as in the IncA/C plasmid. Analysis of the integron showed a novel arrangement of gene cassettes—aacA4, aacC-A1 and bla OXA-21 where the latter might result from an intergeneric gene transfer. The study confirmed Salmonella Kentucky population isolated in Poland belongs to global epidemics of high level fluoroquinolone resistant clone ST198 that can carry rare β-lactamase genes.


      PubDate: 2014-12-16T10:36:42Z
       
  • Emission of ESBL/AmpC-producing Escherichia coli from pig fattening farms
           to surrounding areas
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Christina von Salviati , Henriette Laube , Beatriz Guerra , Uwe Roesler , Anika Friese
      The presence of ESBL/AmpC-producing Escherichia coli in livestock such as pigs has been known for some time. However, to date there is little information about the transmission of these resistant bacteria between pig farms and their surroundings. Thus, the aim of this study was to explore this topic by investigating seven German pig fattening farms. Samples from outside (including ground surfaces, ambient air, slurry and digestate from biogas plants) and, in parallel, from inside the pig barns (including pig feces, dust, barn air, flies and mice feces) were examined for ESBL/AmpC-producing E. coli and selected isolates were compared by pulsed-field gel electrophoresis (PFGE) analysis. 14/17 (82.4%) slurry samples and three of four samples of digestate from biogas plants tested positive for ESBL/AmpC-producing E. coli. In the vicinity of the pig barns these resistant bacteria were detected in 14/87 (16.1%) boot swabs taken from various ground surfaces and in 2/36 (6%) ambient air samples. Inside the pig barns, 6/63 (9.5%) barn air samples and a small proportion of flies and mice feces samples were ESBL/AmpC-positive. PFGE analysis proved fecal emission as well as a possible spread via flies, as identical ESBL-E. coli isolates were detected in slurry and on fertilized fields, as well as in flies and pooled feces from inside the barn and slurry. Contaminated slurry presented the major emission source for ESBL/AmpC-producing E. coli in the pig fattening farms, but a spread via the airborne route or via different vectors also seems possible.


      PubDate: 2014-12-16T10:36:42Z
       
  • Mycoplasma hyopneumoniae-derived lipid-associated membrane proteins induce
           inflammation and apoptosis in porcine peripheral blood mononuclear cells
           in vitro
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Fangfang Bai , Bo Ni , Maojun Liu , Zhixin Feng , Qiyan Xiong , Guoqing Shao
      Mycoplasma hyopneumoniae is the causative agent of swine enzootic pneumonia (EP), a disease that causes considerable economic losss in swine industry. Lipid-associated membrane proteins (LAMPs) of mycoplasma play important roles in causing mycoplasma diseases. The present study explores the pathogenic mechanisms of M. hyopneumoniae LAMPs by elucidating their role in modulating the inflammation, apoptosis, and relevant signaling pathways of peripheral blood mononuclear cells (PBMCs) of pig. LAMP treatment inhibited the growth of PBMCs. Up-regulation of cytokines, such as IL-6 and IL-1β, as well as increased production of nitric oxide (NO) and superoxide anion were all detected in the supernatant of LAMPs-treated PBMCs. Furthermore, flow cytometric analysis using dual staining with annexin-V-FITC and propidium iodide (PI) showed that LAMPs of M. hyopneumoniae induced a time-dependent apoptosis in lymphocyts and monocytes from PBMCs, which was blocked by NOS inhibitor or antioxidant. In addition, LAMPs induced the phosphorylation of p38, the ratio of pro-apoptotic Bax protein to anti-apoptotic Bcl-2, activation of caspase-3 and caspase-8, and poly ADP-ribose polymerase (PARP) cleavage in PBMCs. These findings demonstrated that M. hyopneumoniae LAMPs induced the production of proinflammatory cytokines, NO and reactive oxygen species (ROS), and apoptosis of PBMCs in vitro through p38 MAPK and Bax/Bcl-2 signaling pathways, as well as caspase activation.


      PubDate: 2014-12-16T10:36:42Z
       
  • Variants of a genomic island in Aeromonas salmonicida subsp. salmonicida
           link isolates with their geographical origins
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Jean-Guillaume Emond-Rheault , Antony T. Vincent , Mélanie V. Trudel , Francis Brochu , Brian Boyle , Katherine H. Tanaka , Sabrina A. Attéré , Éric Jubinville , Thomas P. Loch , Andrew D. Winters , Mohamed Faisal , Michel Frenette , Nicolas Derome , Steve J. Charette
      Aeromonas salmonicida subsp. salmonicida is a fish pathogen. Analysis of its genomic characteristics is required to determine the worldwide distribution of the various populations of this bacterium. Genomic alignments between the 01-B526 pathogenic strain and the A449 reference strain have revealed a 51-kb chromosomal insertion in 01-B526. This insertion (AsaGEI1a) has been identified as a new genomic island (GEI) bearing prophage genes. PCR assays were used to detect this GEI in a collection of 139 A. salmonicida subsp. salmonicida isolates. Three forms of this GEI (AsaGEI1a, AsaGEI1b, AsaGEI2a) are now known based on this analysis and the sequencing of the genomes of seven additional isolates. A new prophage (prophage 3) associated with AsaGEI2a was also discovered. Each GEI appeared to be strongly associated with a specific geographic region. AsaGEI1a and AsaGEI2a were exclusively found in North American isolates, except for one European isolate bearing AsaGEI2a. The majority of the isolates bearing AsaGEI1b or no GEI were from Europe. Prophage 3 has also a particular geographic distribution and was found only in North American isolates. We demonstrated that A. salmonicida subsp. salmonicida possesses unsuspected elements of genomic heterogeneity that could be used as indicators to determine the geographic origins of isolates of this bacterium.


      PubDate: 2014-12-16T10:36:42Z
       
  • Impact of mucin, bile salts and cholesterol on the virulence of Vibrio
           anguillarum towards gnotobiotic sea bass (Dicentrarchus labrax) larvae
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Xuan Li , Peter Bossier , Kristof Dierckens , Stanislas Laureau , Tom Defoirdt
      In this study, we investigated the impact of the host factors mucin, bile salts and cholesterol on the virulence of the economically important aquatic pathogen Vibrio anguillarum towards sea bass larvae. Pretreatment of V. anguillarum with either one of the host factors (at 10mgl−1) prior to inoculation into the sea bass rearing water increased virulence of the bacterium, although the effect of cholesterol was not significant. Each of the three host factors significantly increased several virulence-related phenotypes in V. anguillarum, i.e. protease activity, flagellar motility, biofilm formation and exopolysaccharide production, whereas there was no effect on growth of the bacterium under these conditions. Furthermore, the host factors increased the expression of genes involved in these phenotypes, i.e. the metalloprotease empA, the flagellar transcriptional regulator fleQ, the flagellin gene flaA, the chemotaxis methyltransferase gene cheR, the exopolysaccharide biosynthesis gene wbfD and the exopolysaccharide export gene wza. Our results indicate that V. anguillarum uses host mucin, bile salts, and cholesterol as cues to promote the expression of several important virulence traits that enhance the success of transmission from one host to another.


      PubDate: 2014-12-16T10:36:42Z
       
  • A20 promotes Brucella intracellular growth via inhibition of macrophage
           cell death and activation
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Pan Wei , Guimei Cui , Qiang Lu , Li Yang , Zhenhong Guan , Wanchun Sun , Yuxi Zhao , Shuangxi Wang , Qisheng Peng
      The zinc-finger protein A20 has crucial physiological functions as a dual inhibitor of macrophage activation and apoptosis in tumor necrosis factor receptor1 (TNFR1) signaling pathway. Brucella infection can induce A20 expression in macrophages. Here, we hypothesize that A20 promotes Brucella intracellular growth via inhibition of activation and apoptosis of macrophages. To test this hypothesis, we stably incorporated mouse A20-shRNA into the RAW264.7 cells by lentiviral gene transfer to successfully knockdown A20. A20-deficient RAW264.7 cells were subsequently challenged with Brucella abortus and colony formation units (CFUs) of bacteria, TNFα production, NF-kB activation, macrophages apoptosis and cell death were evaluated. The A20 knockdown was shown to effectively promote B. abortus-stimulated TNFα release, NF-kB activation and macrophage cell death, which suppressed B. abortus intracellular replication. Unexpectedly, deficiency of A20 failed to lead to B. abortus-induced macrophage apoptosis. A20 deficiency coupled NF-kB inhibition promoted caspase-8 dependent B. abortus-induced macrophage apoptosis. These findings provide a novel mechanism by which Brucella intracellular growth within macrophages occurs through up-regulation of A20 thereby limiting activation and macrophages cell death.


      PubDate: 2014-12-16T10:36:42Z
       
  • Molecular characterisation of the Mycoplasma cynos haemagglutinin HapA
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Saša Kastelic , Ivanka Cizelj , Mojca Narat , Nataša Tozon , Victoria J. Chalker , Inna Lysnyansky , Joachim Spergser , Dušan Benčina
      Mycoplasma (M.) cynos is a proven pathogen of dogs causing respiratory infections including pneumonia. We examined 19 M. cynos strains isolated from different organs of dogs in Austria, Denmark and Israel. All strains agglutinated mammalian and chicken erythrocytes. Using erythrocytes of chickens or dogs as specific ligands we isolated an approximately 65kDa protein from cell-free supernatants of 3 M. cynos strains, which showed an apparent capacity for haemagglutination. The N-terminal sequence of a 25kDa fragment of this protein was identified as NNEMTPKVTVEAKSMELLLSVEK. The identical amino acid sequence is encoded by the gene MCYN_0308 in the genome of M. cynos C142. This gene belongs to a family of some 20 genes which encode putative lipoproteins with proline-rich regions (PRR) in the first third of their molecules. We termed the 65kDa haemagglutinin HapA and sequenced hapA gene homologues of 16 M. cynos strains. Analyses of hapA gene homologues revealed similar but not identical sequences, some having insertions and/or deletions in the PRR. We produced a recombinant HapA protein (rHapA) and also mouse monoclonal antibodies (mAbs) recognizing HapA. However, enzyme immunoassays using native M. cynos colonies and mAbs 5G2 or 3B7 showed variable expression of HapA in all M. cynos strains. This was further confirmed by Western blot analyses which showed different HapA quantities and also size-variation of HapA among strains. Analyses of cDNA of the expressed hapA genes showed that besides the hapA gene cultures of M. cynos (strains 105, 2002, 2297) can also express other forms of hap genes. In addition, in cloned cultures of strain 2297 altered HapA epitopes for mAbs 5G2 and 3B7 with distinct hapA gene mutations that resulted in altered HapA amino acid sequence were found. Most of the dogs examined had serum antibodies to rHapA. In conclusion, we characterized the M. cynos haemagglutinin HapA protein and encoding gene hapA, a factor involved in cytadherence to host cells and therefore important for M. cynos infection, and showed that expression of HapA is varied in M. cynos by two distinct mechanisms; differential gene expression and nucleic acid substitution within hapA homologues.


      PubDate: 2014-12-16T10:36:42Z
       
  • Application of cattle slurry containing Mycobacterium avium subsp.
           paratuberculosis (MAP) to grassland soil and its effect on the
           relationship between MAP and free-living amoeba
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): M. Salgado , M. Alfaro , F. Salazar , X. Badilla , E. Troncoso , A. Zambrano , M. González , R.M. Mitchell , M.T. Collins
      Slurry from dairy farms is commonly used to fertilize crops and pastures. This mixture of manure, urine and water can harbor multiple microbial pathogens among which Mycobacterium avium subsp. paratuberculosis (MAP) is a major concern. Persistence of MAP in soil and infection of soil Acanthamoeba was evaluated by culture, real-time IS900 PCR, and by staining of amoeba with acid-fast and vital stains comparing soils irrigated with MAP-spiked or control dairy farm slurry. MAP DNA was detected in soil for the 8 month study duration. MAP was detected by PCR from more soil samples for plots receiving MAP-spiked slurry (n =61/66) than from soils receiving control slurry ( n =10/66 samples). Vital stains verified that intracellular MAP in amoeba was viable. More MAP was found in amoeba at the end of the study than immediately after slurry application. There was no relationship between MAP presence in soil and in amoeba over time. Infection of amoeba by MAP provides a protected niche for the persistence and even possibly the replication of MAP in soils. As others have suggested, MAP-infected amoeba may act like a “Trojan horse” providing a means for persistence in soils and potentially a source of infection for grazing animals.


      PubDate: 2014-12-16T10:36:42Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1




      PubDate: 2014-12-16T10:36:42Z
       
  • Serological relationships among subgroups in bovine viral diarrhea virus
           genotype 1 (BVDV-1)
    • Abstract: Publication date: 30 January 2015
      Source:Veterinary Microbiology, Volume 175, Issue 1
      Author(s): Gizem Alpay , Kadir Yeşilbağ
      Bovine viral diarrhea virus (BVDV) has various economic impacts associated with diarrhea, poor performance, an increase in the frequency of other infections and lethal outcomes. Both genotypes, namely BVDV-1 and BVDV-2, as well as different subgroups within these genotypes have been reported worldwide. Understanding the serological differences among the BVDV subgroups is important for disease epidemiology and prevention as well as vaccination programs. The aim of this study was to determine the serological relatedness among the subgroups in BVDV-1. For that purpose, sheep hyperimmune sera were collected against representative strains from 6 of the subgroups of BVDV-1 (BVDV-1a, -1b, -1d, -1f, -1h and -1l). The serum samples that gave the peak antibody titer to the homologous strains were used to perform cross neutralization assays. The highest homologous antibody titer (1:5160) was obtained against BVDV-1h. Regarding the cross neutralizing (heterologous) antibodies, the lowest titer (1:20) was produced by the BVDV-1f antiserum against the BVDV-1a and BVDV1-b viruses. The highest cross neutralizing titer (1:2580) achieved by the BVDV-1h antiserum was against the BVDV-1b strain. The cross neutralization results indicated particular serological differences between the recently described subgroup (BVDV-1l) and BVDV-1a/-1b, which are widely used in commercial vaccines. Considering the cross neutralization titers, it is concluded that selected BVDV-1l and BVDV-1h strains can be used for the development of diagnostic and control tools.


      PubDate: 2014-12-16T10:36:42Z
       
  • Two different genotypes of H1N2 swine influenza virus isolated in northern
           China and their pathogenicity in animals
    • Abstract: Publication date: Available online 9 December 2014
      Source:Veterinary Microbiology
      Author(s): Huanliang Yang , Yan Chen , Chuanling Qiao , Chuantian Xu , Minghua Yan , Xiaoguang Xin , Zhigao Bu , Hualan Chen
      During 2006 and 2007, two swine-origin triple-reassortant influenza A (H1N2) viruses were isolated from pigs in northern China, and the antigenic characteristics of the hemagglutinin protein of the viruses were examined. Genotyping and phylogenetic analyses demonstrated different emergence patterns for the two H1N2 viruses, Sw/Hebei/10/06 and Sw/Tianjin/1/07. Sequences for the other genes encoding the internal proteins were compared with the existing data to determine their origins and establish the likely mechanisms of genetic reassortment. Sw/Hebei/10/06 is an Sw/Indiana/9K035/99-like virus, whereas Sw/Tianjin/1/07 represents a new H1N2 genotype with surface genes of classic swine and human origin and internal genes originating from the Eurasian avian-like swine H1N1 virus. Six-week-old female BALB/c mice infected with the Sw/HeB/10/06 and Sw/TJ/1/07 viruses showed an average weight loss of 12.8% and 8.1%, respectively. Healthy six-week-old pigs were inoculated intranasally with either the Sw/HeB/10/06 or Sw/TJ/1/07 virus. No considerable changes in the clinical presentation were observed post-inoculation in any of the virus-inoculated groups, and the viruses effectively replicated in the nasal cavity and lung tissue. Based on the results, it is possible that the new genotype of the swine H1N2 virus that emerged in China may become widespread in the swine population and pose a potential threat to public health.


      PubDate: 2014-12-11T16:56:49Z
       
  • Pestiviruses infections at the wild and domestic ruminants interface in
           the French Southern Alps
    • Abstract: Publication date: Available online 9 December 2014
      Source:Veterinary Microbiology
      Author(s): Claire Martin , Véronique Duquesne , Gilbert Adam , Eric Belleau , Dominique Gauthier , Jean-Luc Champion , Claude Saegerman , Richard Thiéry , Eric Dubois
      In alpine pasture, interspecies transmission has recently been incriminated in the epidemiology of pestivirus infection. The aim of this study was to investigate pestivirus infections in wild and domestic ruminants sharing pastures in the French Southern Alps. Animal sera were screened for pestivirus antibodies against the pestivirus NS3 protein by a commercial blocking enzyme linked immunosorbent assay (ELISA). All 38 domestic herds tested were positive for pestivirus-specific antibodies. Individual sero-prevalence reached 76.5% (95% confidence interval [95% CI]: [74.2–78.8%]) of the 1,383 sheep tested. For wild ruminants, 38.7% (95% CI: [33.8–43.9%]) of the 369 chamois tested, 28.7% (95% CI: [17.4–38.1%]) of the 72 roe deer, and 22.2% (95% CI: [6.5–37.9%]) of the 27 mouflons were seropositive. Virus screening was carried out on spleen samples from hunted wild animals (n=160) and from 15 domestic ruminants (clinically suspected to be persistently infected animals), by a conventional reverse transcription-polymerase chain reaction (RT-PCR). Three pestivirus strains were isolated from the sheep samples positive by RT-PCR. The viruses were classified in the BDV-3, BDV-Tunisian and BDV-6 genotypes. For the first time, one strain (RUPI-05 strain) was isolated from an alpine chamois and clustered in the BDV-6 genotype, showing in the 5’-UTR region 92% of identity with the ovine isolate from the same area. Thus, an active circulation of pestiviruses was demonstrated in both wild and domestic ungulates from the French Southern Alps. The results suggest that interspecies transmission between sheep and chamois probably occur.


      PubDate: 2014-12-11T16:56:49Z
       
  • The use of quantitative PCR to detect Felis catus papillomavirus type 2
           DNA from a high proportion of queens and their kittens
    • Abstract: Publication date: Available online 11 December 2014
      Source:Veterinary Microbiology
      Author(s): N.A. Thomson , M. Dunowska , J.S. Munday
      Squamous cell carcinomas are common feline skin cancers that have been associated with infection with Felis catus papillomavirus type 2 (FcaPV-2). Currently, little is known about the epidemiology of FcaPV-2 infection. The aim of this study was to develop a real-time PCR assay to quantify FcaPV-2 DNA in plucked hairs and skin swabs from 11 healthy breeding queens and their kittens. Samples were taken prior to kittening and then 2, 7 and 28 days after kittening to determine the age at which the kittens were first exposed to the virus. FcaPV-2 DNA was amplified from all of the queens and from 91% of the kittens at 2 days of age. There was a wide range in the quantity of FcaPV-2 DNA detected, from 1 to 92520 copies per swab, and from 0.01 to 234 copies per copy of reference gene DNA in the hair plucks. The quantity of FcaPV-2 DNA detected in samples collected from the kittens was strongly correlated to that of their respective queens and the mean viral DNA load was similar for cats within a household but varied significantly between households. This is the first time that quantitative PCR has been used to detect FcaPV-2 DNA and the results suggest that the virus is ubiquitous but there is a wide variation of viral DNA loads. Kittens appear to be exposed to FcaPV-2 early in life, presumably from direct contact with their queen. These results are important when determining if FcaPV-2 infection of cats is preventable.


      PubDate: 2014-12-11T16:56:49Z
       
  • Antibodies to Ovine Herpesvirus 2 Glycoproteins Decrease Virus Infectivity
           and Prevent Malignant Catarrhal Fever in Rabbits
    • Abstract: Publication date: Available online 9 December 2014
      Source:Veterinary Microbiology
      Author(s): Cristina W. Cunha , Donald P. Knowles , Naomi S. Taus , Donal O’Toole , Anthony V. Nicola , Hector C. Aguilar , Hong Li
      Ovine herpesvirus-2 (OvHV-2) is the etiological agent of sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease of many species in the order Artiodactyla. Development of a vaccine is critical to prevent mortality. Because OvHV-2 has not been cultured in vitro, SA-MCF research is hindered by the lack of in vitro tools to study viral constituents and specific host immune responses. As an alternative, in this study the neutralizing activity of antibodies against OvHV-2 glycoproteins gB and gH/gL was evaluated in vivo using rabbits. OvHV-2-specific antibodies were developed in rabbits by immunization using biolistic delivery of plasmids expressing the genes of interest. A lethal dose of OvHV-2 was incubated with the antisera and then nebulized into rabbits. Virus neutralization was assessed by measuring infection parameters associated with the virus infectious dose. Anti-gB or anti-gH/gL antibodies alone blocked infection in five out of six rabbits (83%), while a combination of anti-gB and anti-gH/gL antibodies protected all six rabbits (100%) from infection. These results indicate that antibodies to OvHV-2 gB and gH/gL are capable of neutralizing virions, and consequently, reduce virus infectivity and prevent SA-MCF in rabbits. Thus, OvHV-2 gB and gH/gL are suitable targets to be tested in a SA-MCF vaccine aimed at stimulating neutralizing antibody responses.


      PubDate: 2014-12-11T16:56:49Z
       
  • Changes in peripheral blood leukocytes of sheep experimentally infected
           with Mycoplasma agalactiae
    • Abstract: Publication date: Available online 10 December 2014
      Source:Veterinary Microbiology
      Author(s): Mariarosaria Marinaro , Grazia Greco , Elvira Tarsitano , Gianpiero Ventrella , Michele Camero , Marialaura Corrente , Giovanni Rezza , Domenico Buonavoglia
      Contagious agalactia is a serious disease of small ruminants affecting mainly mammary glands, joints and eyes. In sheep, the main aetiological agent is Mycoplasma agalactiae (Ma) whose abilities to persist in the target organs are known. Since there is no information on the effect of acute and chronic Ma infection on circulating leukocytes, the present study was designed to monitor granulocytes, monocytes, T and B lymphocytes, by flow cytometry, in female lactating sheep nasally infected with Ma. A profound depletion of leukocytes was observed from day 5 to day 34 post infection (p.i.). In particular, while the granulocytes returned to baseline levels by day 12 p.i., the monocytes remained significantly low until day 20 p.i. The infection caused a prolonged depletion of peripheral T lymphocytes (both CD4+ and CD8+) while B lymphocytes remained unaltered throughout the study. Mycoplasma agalactiae was detected by real-time PCR in several anatomical sites (ear, nose and milk) from day 2-5 p.i. until the end of the study (i.e., day 50 p.i.) while a transient bacteraemia was observed from day 5 to day 12 p.i. The leukopenia observed following intranasal Ma infection is likely due to leukocyte infiltration within the target organs.


      PubDate: 2014-12-11T16:56:49Z
       
  • Detection and genetic characterization of porcine group A rotaviruses in
           asymptomatic pigs in smallholder farms in East Africa: Predominance of
           P[8] genotype resembling human strains
    • Abstract: Publication date: Available online 10 December 2014
      Source:Veterinary Microbiology
      Author(s): J.O. Amimo , J.O. Junga , W.O. Ogara , A. VlasovaN , M.N. Njahira , S. Maina , E.A. Okoth , R.P. Bishop , L.J. Saif , A. Djikeng
      Viral enteritis is a serious problem accounting for deaths in neonatal animals and humans worldwide. The absence of surveillance programs and diagnostic laboratory facilities have resulted in a lack of data on rotavirus associated diarrheas in pigs in East Africa. Here we describe the incidence of group A rotavirus (RVA) infections in asymptomatic young pigs in East Africa. Of the 446 samples examined, 26.2% (117/446) were positive for RVA. More nursing piglets (78.7%) shed RVA than weaned (32.9%) and grower (5.8%) pigs. RVA incidence was higher in pigs that were either housed_free-range (77.8%) or tethered_free-range (29.0%) than those that were free-range or housed or housed-tethered pigs. The farms with larger herd size (>10 pigs) had higher RVA prevalence (56.5%) than farms with smaller herd size (24.1-29.7%). This study revealed that age, management system and pig density significantly (p<0.01) influenced the incidence of RVA infections, with housed_free-range management system and larger herd size showing higher risks for RVA infection. Partial (811-1604nt region) sequence of the VP4 gene of selected positive samples revealed that different genotypes (P[6], P[8] and P[13]) are circulating in the study area with P[8] being predominant. The P[6] strain shared nucleotide (nt) and amino acid (aa) sequence identity of 84.4-91.3% and 95.1-96.9%, respectively, with known porcine and human P[6] strains. The P[8] strains shared high nt and aa sequence identity with known human P[8] strains ranging from 95.6-100% and 92-100%, respectively. The P[13] strains shared nt and aa sequence identity of 83.6-91.7% and 89.3-96.4%, respectively, only with known porcine P[13] strains. No P[8] strains yielded RNA of sufficient quality/quantity for full genome sequencing. However analysis of the full genome constellation of the P[6], two P[13] and one untypeable strains revealed that the P[6] strain (Ke-003-5) genome constellation was G26-P[6]-I5-R1-C1-M1-A8-N1-T1-E1-H1, P[13] strains (Ug-049 and Ug-453) had G5-P[13]-I5-R1-C1-M1-A8-N1-T7-E1-H1 while the untypeable strain (Ug-218) had G5-P[']-I5-R1-C1-M1-A8-N1-T1-E1-H'. In conclusion, P[6] and P[8] genotypes detected were genetically closely related to human strains suggesting the possibility of interspecies transmission. Further studies are required to determine the role of RVA in swine enteric disease burden and to determine the genetic/antigenic heterogeneity of the circulating strains for development of accurate diagnostic tools and to implement appropriate prophylaxis programs.


      PubDate: 2014-12-11T16:56:49Z
       
  • Multiple amino acid substitutions involved in the adaptation of H6N1 avian
           influenza virus in mice
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Zhijun Yu , Kaihui Cheng , Yue Xin , Weiyang Sun , Xue Li , Jing Huang , Kun Zhang , Songtao Yang , Tiecheng Wang , Xuexing Zheng , Hualei Wang , Yuping Hua , Hongliang Chai , Chuan Qin , Jun Qian , Yuwei Gao , Xianzhu Xia
      H6N1 avian influenza viruses (AIVs) are one of the most abundantly detected avian influenza virus subtype, and a human H6N1 infection case has been reported in 2013. H6N1 AIVs may pose a potential human risk, however, the factors that promote the replication of H6N1 viruses in mammals remain poorly understood. Here, we generated mouse-adapted variants of a H6N1 virus (A/Mallard/SanJiang/275/2007) to identify adaptive changes that confer enhanced virulence to H6N1 viruses in mammals. After eight sequential passages in mice, the mouse lethal doses (MLD50) of the variants were reduced >1000-fold compared to the parental virus. We found that the variants displayed the greatest enhancement of replication in vitro and in vivo, and also were capable of replicating in the brains of infected mice. These observations suggest that enhanced growth characteristics and modified cell tropism may contribute to increased virulence of H6N1 AIVs in mice. Sequencing of the variants revealed amino acid changes in the PB2 (E627K), PA (T97I), and HA (N394T) proteins. Our results suggest that these mutations involved in the enhancement of the ability of H6N1 virus to efficient replicate and cause severe disease in mammals.


      PubDate: 2014-11-29T16:21:43Z
       
  • Study of the virulence of serotypes 4 and 9 of African horse sickness
           virus in IFNAR−/−, Balb/C and 129 Sv/Ev mice
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Maria Ana de la Grandière , Fabiana Dal Pozzo , Marylène Tignon , William Zonta , Damien Thiry , Axel Mauroy , Élisabeth Mathijs , Ann Brigitte Caij , Claude Saegerman , Étienne Thiry
      African horse sickness virus (AHSV) is a double-stranded RNA virus which belongs to the family Reoviridae, genus Orbivirus. Recent studies have focused on the interferon-α/β receptor knock-out mice (IFNAR−/−) as a small animal laboratory for the development of AHSV vaccines. The aim of this work was to study in vivo the virulence of two strains of AHSV and to compare the outcome of the infection of three mouse strains. To address this, AHSV serotypes 4 (AHSV-4) and 9 (AHSV-9) were inoculated subcutaneously (SC) and intranasally (IN) in two immunocompetent mouse strains (Balb/C and 129 Sv/Ev (129 WT)) as well as IFNAR−/− mice (on 129 Sv/Ev genetic background). In IFNAR−/− mice, fatality up to 50% was measured and significantly more clinical signs were observed in comparison with SC inoculated immunocompetent mice. The observed clinical signs were significantly more severe after AHSV-4 infection, in particular in immunocompetent mice inoculated by IN route. Considering RNAemia, significantly higher viral loads were measured following AHSV-4 infection. In the organs of 129 WT inoculated by IN route, significantly higher viral loads were detected after AHSV-4 infection. Together the results support a higher virulence for AHSV-4 compared to AHSV-9 and a higher clinical impact following infections in IN inoculated mice, at least in the investigated strains. The study also brought indirect evidences for type I IFN involvement in the control of AHSV infection.


      PubDate: 2014-11-29T16:21:43Z
       
  • Genetic characterization of hepadnaviruses associated with
           histopathological changes in the liver of duck and goose embryos
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Marina Biđin , Marina Tišljar , Zdenko Biđin , Ivana Lojkić , Darko Majnarić
      Avian hepadnaviruses are etiological agents of hepatitis B, that has been identified primarily in ducks, and more recently in various avian species. In this paper, 16 hepadnaviruses were detected by polymerase chain reaction (PCR) in the field samples from dead embryos of commercially reared domestic duck and goose. Based on the molecular analysis of the S-protein gene sequences and phylogenetic Neighbor-joining tree, identified viruses were clustered in the same genetic group, indicating no host-related diversity. Both duck and goose-origin hepadnaviruses were grouped within the cluster consisting of “Western-country” and “Chinese” duck hepatitis B (DHBV) isolates, showing more evolutionary distances with other known avian hepadnaviruses. Histopathologically, the lesions observed in the liver tissue from hepadnavirus positive duck and goose embryos varied from low to mild degree of perivascular mononuclear cells and mixed cell infiltrations, followed by mild vacuolar changes. Small focal necrotic changes in the liver parenchyma, and bile ductular proliferation were also found in examined liver samples. Generally, the microscopic findings resemble those described in experimentally infected ducks, while this was the first description of hepadnavirus associated lesions in domestic goose. Although hepadnaviruses are considered to have a very narrow host range, this study showed that domestic ducks and geese are susceptible to infection with genetically almost identical hepadnaviruses, that were likely to produce similar microscopic changes in the liver of both duck and goose embryos. The impact of naturally occurred hepadnavirus infection and possible synergistic interactions with other infectious or non-infectious agents on embryo viability needs further investigation.


      PubDate: 2014-11-29T16:21:43Z
       
  • Enzootic genotype S of H9N2 avian influenza viruses donates internal genes
           to emerging zoonotic influenza viruses in China
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Min Gu , Hongzhi Chen , Qunhui Li , Junqing Huang , Mingjun Zhao , Xiaobing Gu , Kaijun Jiang , Xiaoquan Wang , Daxin Peng , Xiufan Liu
      Avian influenza viruses of subtype H9N2 are widely prevalent in poultry in many Asian countries, and the segmented nature of the viral genome results in multiple distinct genotypes via reassortment. In this study, genetic evolution of H9N2 viruses circulating in eastern China during 2007–2013 was analyzed. The results showed that the diversity of the gene constellations generated six distinct genotypes, in which a novel genotype (S) bearing the backbone of A/chicken/Shanghai/F/98-like viruses by acquiring A/quail/Hong Kong/G1/97-like polymerase basic subunit 2 and matrix genes has gradually established its ecological niche and been consistently prevalent in chicken flocks in eastern China since its first detection in 2007. Furthermore, genotype S possessed the peculiarity to donate most of its gene segments to other emerging influenza A viruses in China, including the novel reassortant highly pathogenic avian influenza H5N2, the 2013 novel H7N7, H7N9 and the latest reassortant H10N8 viruses, with potential threat to poultry industry and human health.


      PubDate: 2014-11-29T16:21:43Z
       
  • Engineering the PRRS virus genome: Updates and perspectives
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Mingyuan Han , Dongwan Yoo
      Porcine reproductive and respiratory syndrome virus (PRRSV) is endemic in most pig producing countries worldwide and causes enormous economic losses to the pork industry. Infectious clones for PRRSV have been constructed, and so far at least 14 different infectious clones are available representing both genotypes I and II. Two strategies have been taken for progeny reconstitution: RNA transfection and DNA transfection. Mutations, insertions, deletions, and replacements of the viral genome have been employed to study the structure function relationship, foreign gene expression, functional complementation, and virulence determinants. Essential regions and non-essential regions for viral replication have been identified in both the coding regions and non-encoding regions. Foreign sequences have successfully been inserted into the nsp2 and N regions and in the space between ORF1b and ORF2a. Chimeras between member viruses in the family Arteriviridae have also been constructed and utilized to study cell tropism and functional complementation. This review discusses the advances and utilization of PRRSV reverse genetics and its potential for future research.


      PubDate: 2014-11-29T16:21:43Z
       
  • Effect of porcine circovirus type 2 (PCV2) load in serum on average daily
           weight gain during the postweaning period
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): S. López-Soria , M. Sibila , M. Nofrarías , M. Calsamiglia , E.G. Manzanilla , H. Ramírez-Mendoza , A. Mínguez , J.M. Serrano , O. Marín , F. Joisel , C. Charreyre , J. Segalés
      Porcine circovirus type 2 (PCV2) is a ubiquitous virus that mainly affects nursery and fattening pigs causing systemic disease (PCV2-SD) or subclinical infection. A characteristic sign in both presentations is reduction of average daily weight gain (ADWG). The present study aimed to assess the relationship between PCV2 load in serum and ADWG from 3 (weaning) to 21 weeks of age (slaughter) (ADWG 3-21). Thus, three different boar lines were used to inseminate sows from two PCV2-SD affected farms. One or two pigs per sow were selected (60, 61 and 51 piglets from Pietrain, Pietrain×Large White and Duroc×Large White boar lines, respectively). Pigs were bled at 3, 9, 15 and 21 weeks of age and weighted at 3 and 21 weeks. Area under the curve of the viral load at all sampling times (AUCqPCR 3-21) was calculated for each animal according to standard and real time quantitative PCR results; this variable was categorized as “negative or low” (<104.3 PCV2 genome copies/ml of serum), “medium” (≥104.3 to ≤105.3) and “high” (>105.3). Data regarding sex, PCV2 antibody titre at weaning and sow parity was also collected. A generalized linear model was performed, obtaining that paternal genetic line and AUCqPCR 3-21 were related to ADWG 3-21. ADWG 3-21 (mean±typical error) for “negative or low”, “medium” and “high” AUCqPCR 3-21 was 672±9, 650±12 and 603±16g/day, respectively, showing significant differences among them. This study describes different ADWG performances in 3 pig populations that suffered from different degrees of PCV2 viraemia.


      PubDate: 2014-11-29T16:21:43Z
       
  • IFC - Aims &amp; Scope, EDB, Publication Information
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4




      PubDate: 2014-11-29T16:21:43Z
       
  • A monoclonal antibody recognizes a highly conserved neutralizing epitope
           on hemagglutinin of H6N1 avian influenza virus
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Jie-Long He , Ming-Shou Hsieh , Rong-Huay Juang , Ching-Ho Wang
      Neutralizing antibodies on the globular head of the hemagglutinin (HA) of avian influenza virus (AIV) are crucial for controlling this disease. However, most neutralizing antibodies lack cross reaction. This report describes the identification of a hemagglutinin epitope on the globular head near the receptor binding site of the H6N1 AIV. A monoclonal antibody named EB2 was prepared against the H6N1 AIV HA. Flow cytometry of AIV-infected chicken embryo fibroblast, DF-1 cells and specific-pathogen-free embryonated eggs were used to verify the neutralizing activity of this mAb. To narrow down the binding region, partially overlapping HA fragments and synthetic peptides were used to map the epitope by immune-blotting. The linear motif RYVRMGTESMN, located on the surface on the globular head of the HA protein, was identified as the epitope bound by EB2 mAb. Alignment of the EB2-defined epitope with other H6 AIVs showed that this epitope was conserved and specific to H6. We propose that this motif is a linear B-cell epitope of the HA protein and is near the receptor binding site. The identified epitope might be useful for clinical applications and as a tool for further study of the structure and function of the AIV HA protein.


      PubDate: 2014-11-29T16:21:43Z
       
  • Molecular characterization of group B rotavirus circulating in pigs from
           India: Identification of a strain bearing a novel VP7 genotype, G21
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Anismrita Lahon , Vijay C. Ingle , Hemant S. Birade , Chandrasekhar G. Raut , Shobha D. Chitambar
      The occurrence of group B rotavirus (RVB) infections in pigs has been reported from different parts of world. However, such infection in the pig population maintained in Indian farms has not been investigated as yet. A total of 187 faecal specimens were collected from pigs reared in different pig farms/pigsties located in western and northern regions of India and tested for the presence of porcine RVB by amplification of the NSP2 gene using conventional RT-PCR. Nine specimens (4.8%) were shown to contain RVB RNA. N2 and N4 genotypes of NSP2 gene were detected in three and six RVB strains respectively. VP7 (G-type) and NSP5 (H-type) genes of selected six RVB strains were characterized to identify the genotypes. Multiple G (G7, G19 and G20) and H (H4 and H5) genotypes detected in the RVB strains indicated circulation of heterogeneous population of RVB strains in pigs of India. Additionally, one strain was proposed to belong to a novel RVB genotype designated as G21 on account of <80% identity of VP7 gene sequence with its counterpart in RVB strains from 20 established genotypes. Deduced amino acid sequence of VP7 gene also displayed the presence of seven unique substitutions in the strain. The study reports for the first time the occurrence of RVB infections in Indian pig herds and provides important epidemiological data useful for better understanding of ecology and evolution of porcine RVBs.


      PubDate: 2014-11-29T16:21:43Z
       
  • Quantification of different classical swine fever virus transmission
           routes within a single compartment
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Eefke Weesendorp , Jantien Backer , Willie Loeffen
      During outbreaks of classical swine fever (CSF), CSF virus (CSFV) can be transmitted via different routes. Understanding these transmission routes is crucial in preventing the unlimited spread of the virus in a naïve population, and the subsequent eradication of the virus from that population. The objectives of the present study were to quantify virus transmission within a compartment, differentiating between transmission within a pen, transmission between pens via contact through (open) pen partitions, and transmission via the air. Furthermore, the possible contribution of each of these routes to infection of individual pigs was quantified. A CSFV outbreak was mimicked in a compartment housing 24 pigs in six different pens. Two pigs in one pen were inoculated with the moderately virulent Paderborn strain, and virus transmission to other pigs was followed in time. Virus transmission rates for transmission via the air (β of 0.33 (0.14–0.64) per day) and transmission between adjacent pens (β of 0.30 (0–0.88) per day) were comparable, but significantly lower than for virus transmission within a pen (β of 6.1 (0.86–18) per day). The route via the air created new focal points of infection, from which virus transmission continued through other routes. This shows that, at least within a compartment, transmission via the air is expected to play a relevant role in the fast spread of the virus after an initial slow start. This will have consequences for efficacy of intervention measures, including vaccination during an outbreak.


      PubDate: 2014-11-29T16:21:43Z
       
  • Recombinant rabies virus expressing the H protein of canine distemper
           virus protects dogs from the lethal distemper challenge
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Feng-Xue Wang , Shu-Qin Zhang , Hong-Wei Zhu , Yong Yang , Na Sun , Bin Tan , Zhen-Guang Li , Shi-Peng Cheng , Zhen F. Fu , Yong-Jun Wen
      The rabies virus (RV) vector LBNSE expressing foreign antigens have shown considerable promise as vaccines against viral and bacteria diseases, which is effective and safe. We produced a new RV-based vaccine vehicle expressing 1.824kb hemagglutinin (H) gene of the canine distemper virus (CDV) by reverse genetics technology. The recombinant virus LBNSE-CDV-H retained growth properties similar to those of vector LBNSE both in BSR and mNA cell culture. The H gene of CDV was expressed and detected by immunostaining. To compare the immunogenicity of LBNSE-CDV-H, dogs were immunized with each of these recombinant viruses by intramuscular (i.m.). The dogs were bled at third weeks after the immunization for the measurement of virus neutralizing antibody (VNA) and then challenged with virulent virus (ZJ 7) at fourth weeks. The parent virus (LBNSE) without expression of any foreign molecules was included for comparison. Dogs inoculated with LBNSE-CDV-H showed no any signs of disease and exhibited seroconversion against both RV and CDV H protein. The LBNSE-CDV-H did not cause disease in dogs and conferred protection from challenge with a lethal wild type CDV strain, demonstrating its potential value for wildlife conservation efforts. Together, these studies suggest that recombinant RV expressing H protein from CDV stimulated high levels of adaptive immune responses (VNA), and protected all dogs challenge infection.


      PubDate: 2014-11-29T16:21:43Z
       
  • Characterization of two recent Japanese field isolates of canine distemper
           virus and examination of the avirulent strain utility as an attenuated
           vaccine
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Akiko Takenaka , Misako Yoneda , Takahiro Seki , Masashi Uema , Takanori Kooriyama , Toshiya Nishi , Kentaro Fujita , Ryuichi Miura , Kyoko Tsukiyama-Kohara , Hiroki Sato , Chieko Kai
      Recently, several new strains of canine distemper virus (CDV) have been isolated in Japan. To investigate their pathogenesis in dogs, the Yanaka and Bunkyo-K strains were investigated by infecting dogs and determining clinical signs, amount of virus, and antibody responses. The Yanaka strain is avirulent and induced an antibody response. The Bunkyo-K strain induced typical CDV clinical signs in infected dogs and virulence was enhanced by brain passage. Molecular and phylogenetic analyses of H genes demonstrated the Bunkyo-K strains were of a different lineage from Asia-1 group including the Yanaka strain and Asia-2 group that contain recent Japanese isolates, which were recently identified as major prevalent strains worldwide but distinct from old vaccine strains. Based on these data, we tested the ability of the Yanaka strain for vaccination. Inoculation with the Yanaka strain efficiently induced CDV neutralizing antibodies with no clinical signs, and the protection effects against challenge with either old virulent strain or Bunkyo-K strain were equal or greater when compared with vaccination by an original vaccine strain. Thus, the Yanaka strain is a potential vaccine candidate against recent prevalent CDV strains.


      PubDate: 2014-11-29T16:21:43Z
       
  • Immunological responses and protection in Chinese giant salamander Andrias
           davidianus immunized with inactivated iridovirus
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Wenzhi Liu , Jin Xu , Jie Ma , Scott E. LaPatra , Yan Meng , Yuding Fan , Yong Zhou , Xin Yang , Lingbing Zeng
      Chinese giant salamander hemorrhage is a newly emerged infectious disease in China and has caused huge economic losses. The causative pathogen has been identified as the giant salamander iridovirus (GSIV). In this study, the immunological responses and protection in Chinese giant salamander immunized with β-propiolactone inactivated GSIV are reported. Red and white blood cell counting and classification, phagocytic activity, neutralizing antibody titration, immune-related gene expression and determination of the relative percent survival were evaluated after vaccination. The red and white blood cell counts showed that the numbers of erythrocytes and leukocytes in the peripheral blood of immunized Chinese giant salamanders increased significantly on days 4 and 7 post-injection (P <0.01). Additionally, the differential leukocyte count of monocytes and neutrophils were significantly different compared to the control group (P <0.01); the percentage of lymphocytes was 70.45±7.52% at day 21. The phagocytic percentage and phagocytic index was 38.78±4.33% and 3.75±0.52, respectively, at day 4 post-immunization which were both significantly different compared to the control group (P <0.01). The serum neutralizing antibody titer increased at day 14 post-immunization and reached the highest titer (341±9.52) at day 21. The quantitative PCR analysis revealed that the immunization significantly up-regulated the expression of immune related genes TLR-9 and MyD88 the first two weeks after immunization. The challenge test conducted at day 30 post-injection demonstrated that the immunized group produced a relative survival of 72%. These results indicate that the inactivated GSIV could elicit significant non-specific and specific immunological responses in Chinese giant salamander that resulted in significant protection against GSIV induced disease.


      PubDate: 2014-11-29T16:21:43Z
       
  • Effects of the nuclear localization of the Npro protein of classical swine
           fever virus on its virulence in pigs
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Yongfeng Li , Liang Shen , Yuan Sun , Xiao Wang , Chao Li , Junhua Huang , Jianing Chen , Lianfeng Li , Bibo Zhao , Yuzi Luo , Su Li , Hua-Ji Qiu
      The Npro protein of classical swine fever virus (CSFV) is localized in the cytoplasm and nucleus. However, it is unknown whether the nuclear localization of Npro correlates with the virulence of CSFV in the host. Previously, we showed that the Npro protein fused with interferon regulatory factor 3 (IRF3) was present only in the cytoplasm. Here, we generated and evaluated a recombinant CSFV vSM-IRF3 harboring the IRF3 gene inserted into the Npro gene of the highly virulent CSFV Shimen strain. Compared to the even nuclear and cytoplasmic distribution of the enhanced green fluorescent protein (EGFP)-Npro fusion expressed by the recombinant CSFV EGFP-CSFV, vSM-IRF3 expressed an IRF3-Npro fusion protein that only was localized in the cytoplasm. vSM-IRF3 was markedly attenuated in vitro and in vivo, and the inoculated pigs were completely protected from lethal CSFV challenge, whereas the parental virus as well as EGFP-CSFV exhibited a typical virulent phenotype. Taken together, the nuclear localization of Npro plays a significant role in the CSFV replication and virulence.


      PubDate: 2014-11-29T16:21:43Z
       
  • Pestiviral Erns blocks TLR-3-dependent IFN synthesis by LL37 complexed RNA
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Christoph Zürcher , Kay-Sara Sauter , Matthias Schweizer
      The ribonuclease activity of the soluble glycoprotein Erns of pestiviruses represents a unique mechanism to circumvent the host's innate immune system by blocking interferon type-I synthesis in response to extracellularly added single- (ss) and double-stranded (ds) RNA. However, the reason why pestiviruses encode a ribonuclease in addition to the abundant serum RNases remained elusive. Here, we show that the 5′ UTR and NS5B regions of various strains of the RNA genome of the pestivirus bovine viral diarrhea virus (BVDV) are resistant to serum RNases and are potent TLR-3 agonists. Inhibitory activity of Erns was restricted to cleavable RNA products, and did not extend to the synthetic TLR-7/8 agonist R-848. RNA complexed with the antimicrobial peptide LL37 was protected from degradation by Erns in vitro but was fully inhibited by Erns in its ability to induce IFN in cell cultures, suggesting that the viral protein is mainly active in cleaving RNA in an intracellular compartment. We propose that secreted Erns represents a potent IFN antagonist, which degrades viral RNA that is resistant to the ubiquitous host RNases in the extracellular space. Thus, the viral RNase prevents its own pathogen-associated molecular pattern (PAMP) to inadvertently activate the IFN response that might break innate immunotolerance required for persistent pestivirus infections.


      PubDate: 2014-11-29T16:21:43Z
       
  • GP5 expression in Marc-145 cells inhibits porcine reproductive and
           
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Jiming Gao , Pengchao Ji , Maodong Zhang , Xiangpeng Wang , Na Li , Chengbao Wang , Shuqi Xiao , Yang Mu , Qin Zhao , Taofeng Du , Yani Sun , Julian A. Hiscox , Gaiping Zhang , En-Min Zhou
      The major neutralizing epitope of porcine reproductive and respiratory syndrome virus (PRRSV) is mainly located on virus glycoprotein 5 (GP5). Immunization with exogenous GP5 or exposure to native GP5 by means of DNA immunization can provide some degree of immune protection to PRRSV infection in pigs. However, during PRRSV infection in pigs, the production of neutralization antibodies induced by GP5 is delayed or suppressed. This suggests that the synthesis of GP5 is late than some PRRSV proteins or other PRRSV proteins interfering with the function of GP5 in inducing host responses during virus infection. Here, to exclude the impacts of the other PRRSV proteins and determine the role of GP5 in the replication of PRRSV in vitro, a Marc-145 cell line stably expressing GP5 (Marc-145-GP5Flag) was constructed. Cell proliferation and cell apoptosis measurements indicated that the expression of GP5 in Marc-145 cells did not disturb the cells’ viability. Following infection with different PRRSV strains PRRSV replication in Marc-145-GP5Flag cells was inhibited significantly. Type I interferon assay results showed that beta interferon (IFN-β) in the Marc-145-GP5Flag cells were increased at mRNA and protein levels. When siRNA was introduced into the cells to knock down IFN-β mRNA, PRRSV infectivity of these cells was recovered. These data suggest that early GP5 expression is not favorable for further infection by PRRSV, because it not only stimulates production of neutralization antibodies in pigs, but also induces IFN-β production in host cells. Therefore, GP5 is an important protein in the induction of self-protection responses from the host.


      PubDate: 2014-11-29T16:21:43Z
       
  • In vivo effect of deoxynivalenol (DON) naturally contaminated feed on
           porcine reproductive and respiratory syndrome virus (PRRSV) infection
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Christian Savard , Vicente Pinilla , Chantale Provost , Carl A. Gagnon , Younes Chorfi
      Deoxynivalenol (DON), also known as vomitoxin, is the most prevalent type B trichothecene mycotoxin worldwide. Pigs show a great sensitivity to DON, and because of the high proportion of grains in their diets, they are frequently exposed to this mycotoxin. The objective of this study was to determine the impact of DON naturally contaminated feed on porcine reproductive and respiratory syndrome virus (PRRSV) infection, the most important porcine viral pathogen in swine. Experimental infections were performed with 30 animals. Piglets were randomly divided into three groups of 10 animals based on DON content of diets (0, 2.5 and 3.5mg/kg DON). All experimental groups were further divided into subgroups of 6 pigs and were inoculated with PRRSV. The remaining pigs (control) were sham-inoculated with PBS. Pigs were daily monitored for temperature, weight and clinical signs for 21 days. Blood samples were collected and tested for PRRSV RNA and for virus specific antibodies. Results of PRRSV infection showed that ingestion of diet highly contaminated with DON greatly increases the effect of PRRSV infection on weight gain, lung lesions and mortality, without increasing significantly viral replication, for which the tendency is rather directed toward a decrease of replication. These results suggest that PRRSV infection could exacerbate anorectic effect of DON, when ingested in large doses. Results also demonstrate a DON negative effect on PRRSV-specific humoral responses. This study demonstrate that high concentrations of DON naturally contaminated feed decreased the immune response against PRRSV and influenced the course of PRRSV infection in pigs.


      PubDate: 2014-11-29T16:21:43Z
       
  • Survivability of porcine epidemic diarrhea virus (PEDV) in bovine plasma
           submitted to spray drying processing and held at different time by
           temperature storage conditions
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Joan Pujols , Joaquim Segalés
      Bovine plasma was inoculated with porcine epidemic diarrhea virus (PEDV) at an average final titer of 4.2 log10 TCID50/mL to determine the effect of spray drying on viral inactivation. Using a laboratory scale drier, inoculated plasma was spray dried at 200°C inlet temperature and either 70 or 80°C throughout substance. Both liquid and dried samples were subjected to three passages on VERO cell monolayers to determine PEDV infectivity. Results indicated liquid samples contained infective virus, but none of the spray dried samples were infectious. Also, survivability of PEDV inoculated on spray dried bovine plasma (SDBP) and stored at 4, 12 or 22°C was determined for 7, 14 and 21 days. Commercial SDBP powder was inoculated with PEDV to an average final titer of 2.8 log10 TCID50/g. Five samples per time and temperature conditions were subjected to three passages on VERO cell monolayers to determine PEDV infectivity. The virus was non-infectious for all samples stored at 22°C at 7, 14 and 21 days. PEDV was infective in 1 out of 5 samples stored at 12°C at 7 days, but none of the samples stored for 14 and 21 days were infectious in cell culture. For samples stored at 4°C, 4 out of 5 samples were infectious at 7 days, 1 out of 5 samples were infectious at 14 days, but none were infectious at 21 days. In summary, PEDV was not infectious on cell culture within 7 days when stored at room temperature and within 21 days when stored at refrigerated temperature.


      PubDate: 2014-11-29T16:21:43Z
       
  • Effects of ocular surface strontium-90 beta radiotherapy in dogs latently
           infected with canine herpesvirus-1
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Amanda M. Nicklin , Margaret C. McEntee , Eric C. Ledbetter
      Latent canine herpesvirus-1 (CHV-1) infections are common in domestic dogs, but stimuli causing viral reactivation and recrudescent disease are poorly understood. Immunosuppressive pharmaceuticals are currently the only experimentally established triggers for recurrent ocular CHV-1 infection in dogs; however, ocular CHV-1 shedding has been reported clinically following strontium-90 beta radiotherapy of the ocular surface and it has been speculated that radiotherapy can directly induce viral reactivation. Strontium-90 is used as a beta radiation source for the treatment of a variety of neoplastic and immune-mediated canine ocular surface diseases. In the present study, the effects of ocular surface strontium-90 beta radiotherapy in dogs latently infected with CHV-1 were evaluated. Ten mature dogs with experimentally induced latent CHV-1 infections were randomly divided into two groups: one group received a single fraction 50Gy radiation dose in one application from a strontium-90 ophthalmic applicator and the second group received sham radiotherapy. Dogs were then monitored for 45 days for recurrent ocular CHV-1 infection using clinical and virological outcome measures. Clinical ophthalmic examinations, ocular sample CHV-1 PCR assays, and serum CHV-1 virus neutralizing antibody assays were performed at specified intervals. No abnormalities suggestive of recurrent CHV-1 ocular disease were observed on clinical examination in any dog during the study. Ocular viral shedding was not detected and CHV-1 virus neutralizing titers remained stable in all dogs. A single fraction 50Gy radiation dose administered to the ocular surface by strontium-90 beta radiotherapy did not result in detectable recurrent ocular CHV-1 infection in mature dogs with experimentally induced latent infection.


      PubDate: 2014-11-29T16:21:43Z
       
  • Identification and characterisation of small molecule inhibitors of feline
           coronavirus replication
    • Abstract: Publication date: 5 December 2014
      Source:Veterinary Microbiology, Volume 174, Issues 3–4
      Author(s): Phillip McDonagh , Paul A Sheehy , Jacqueline M Norris
      Feline infectious peritonitis (FIP), a feline coronavirus (FCoV) induced disease, is almost invariably fatal with median life expectancy measured in days. Current treatment options are, at best, palliative. The objectives of this study were to evaluate a panel of nineteen candidate compounds for antiviral activity against FCoV in vitro to determine viable candidates for therapy. A resazurin-based cytopathic effect inhibition assay, which detects viable cells through their reduction of the substrate resazurin to fluorescent resorufin, was developed for screening compounds for antiviral efficacy against FCoV. Plaque reduction and virus yield reduction assays were performed to confirm antiviral effects of candidate compounds identified during screening, and the possible antiviral mechanisms of action of these compounds were investigated using virucidal suspension assays and CPE inhibition and IFA-based time of addition assays. Three compounds, chloroquine, mefloquine, and hexamethylene amiloride demonstrated marked inhibition of virus induced CPE at low micromolar concentrations. Orthogonal assays confirmed inhibition of CPE was associated with significant reductions in viral replication. Selectivity indices calculated based on in vitro cytotoxicity screening and reductions in extracellular viral titre were 217, 24, and 20 for chloroquine, mefloquine, and hexamethylene amiloride respectively. Preliminary experiments performed to inform the antiviral mechanism of the compounds demonstrated all three acted at an early stage of viral replication. These results suggest that these direct acting antiviral compounds, or their derivatives, warrant further investigation for clinical use in cats with FIP.


      PubDate: 2014-11-29T16:21:43Z
       
 
 
JournalTOCs
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Email: journaltocs@hw.ac.uk
Tel: +00 44 (0)131 4513762
Fax: +00 44 (0)131 4513327
 
About JournalTOCs
API
Help
News (blog, publications)
JournalTOCs on Twitter   JournalTOCs on Facebook

JournalTOCs © 2009-2014